To decompose odorous components contained in the air by using electrical energy, a deodorization apparatus is proposed in which a hydrogen-ion-conductive electrolyte layer is sandwiched between two electrodes, one (anode) of the electrodes is provided with a gas introduction path, and a voltage is applied between the anode and cathode electrodes to decompose odorous gases (Patent Literature 1). According to this deodorization apparatus, a voltage is applied between the two electrodes so that odorous gases such as acetaldehyde are decomposed and deodorized through an anode reaction. As for this deodorization apparatus, an example in which sulfuric acid is used as an electrolyte and an example in which an ion-conductive resin having hydrogen-ion (proton) conductivity is used as an electrolyte are disclosed. Here, the electrode is formed by applying fine catalytic particles of platinum, ruthenium, iridium, or the like carried by a carbon powder to a porous carbon substrate and firing the resultant porous carbon substrate. Thus, odorous gases such as acetaldehyde, formaldehyde, ethanol, and methanol can be decomposed.
The above-described sulfuric acid is a well known electrolytic solution. The above-described ion-conductive resin is a well known polymeric resin generally referred to as a “perfluorocarbon (PFC) cation exchange polymer”. As for PFC polymer membranes in which sulfonic acid groups and carboxylic acid groups are used as ion exchange groups, for example, there is “Nafion” (registered trademark) manufactured by E.I. du Pont de Nemours and Company. Since such PFC polymers lose their ion conductivity without moisture, moisture is necessarily required.